Chapter 2 part A

Question 1

How is temperature closely related to internal energy ?

Answer 1

Internal Energy consists of two main components: Kinetic E and Potential E. Temperature is closely related to the kinetic part since temperature is a measure of the average kinetic E. Therefore, the faster the molecules in a substance move (i.e., the higher their kinetic energy), the higher the temperature of the substance.

Question 2

At absolute zero (0k) what would the internal energy related to kinetic motion look like?

Answer 2

At absolute zero (0 K), the internal energy related to kinetic motion would be at its minimum, with atomic motion ceasing.

Question 3

At cooler temperature, what would the internal energy related to kinetic motion look like?

Answer 3

Slower atomic motions: cooler temperatures

Question 4

True or False?
Heat is the measure of how “hot/cold” a substance is

Answer 4

False
Energy transferred between objects due to a temperature difference
BUT NOT the measure of how “hot/cold” a substance is

Question 5

What type of heat is the associate to change in temperature and the heat exchange we can feel?

Answer 5

Sensible heat

Question 6

Which type of heat is required for phase transition of a substance?

Answer 6

Latent Heat

Question 7

What explains that oceans take longer to heat up in summer?

Answer 7

Water has a much higher specific heat than air (by a factor of four). Oceans take longer to heat up in summer but are also slower to cool in winter (compared to heating/cooling of air).

Question 8

By what factor does specific heat capacity of air & water differ?

Answer 8

Water has a much higher specific heat than air (by a factor of four)

Question 9

What are the different phases & their associated molecular configurations?

Answer 9

Solid: Compact, ordered structure.
Liquid: Compact, disordered state.
Gas: Low-density, disordered state.

Question 10

What phase changes of H20 cools the environment?

Answer 10

Heat absorption of H20 happens in melting & evaporation
Ice → Liquid (melting).
Ice → Vapor (sublimation).
Liquid → Vapor (evaporation)

Question 11

What phase changes of H20 warms the environment?

Answer 11

Heat Release: freezing & condensation
Liquid → Ice (freezing).
Vapor → Ice (deposition).
Vapor → Liquid (condensation).

Question 12

How is latent heat an important driver for global circulation?

Answer 12

Transport of water vapour followed by release of latent heat at different locations in the atmosphere

Question 13

What is the importance of Latent Heat in Atmospheric Processes?

Answer 13

Condensation and freezing (release heat)
-Cumulus cloud convection
-Mid-latitude cyclones and hurricanes.
-Global circulation through water vapor transport and heat release.

Evaporation: from Earth’s surface and from clouds / precipitation cools the air and supplies moisture to the air (increasing the humidity).

Question 14

What are the mechanisms for heat transfer in the atmosphere

Answer 14

*Conduction(molecular motion - ex: air nea the Earth’ surface)
*Convection (macroscopic fluid motion)
*Radiation(electromagnetic waves- ex: energy from the sun)

Question 15

Which substances have faster molecular motion? Why?

Answer 15

Warmer substances
-translation
-rotation
-vibration

Question 16

Why is conduction a molecular transfer of heat from warm to cold regions?

Answer 16

Collisions with near by molecules imparting momentum and energy

Question 17

What is thermal conductivity?

Answer 17

Thermal conductivity: efficiency in transferring heat by molecular motion

Question 18

Good vs poor conductors

Answer 18

Good conductors conduct heat more efficiently: Silver & copper are excellent conductors

Poor conductors are good insulators: Air is a rather poor conductor

Question 19

Define the components convection is seperated in, in atmosphere

Answer 19

*Advection: transfer by bulk air motion (horizontal or vertical transport by the wind)

*“Atmospheric” convection: turbulent vertical circulations driven by buoyancy (density) differences

Question 20

Define air parcel

Answer 20

A coherent sample of air that moves freely but does not exchange heat with its surroundings
Maintains the same pressure (but not temperature or density) as its surroundings at the same height
Imagine a balloon floating through the air

Question 21

What determines air parcel’s vertical motion?

Answer 21

Density (positively vs negatively buoyant)

Question 22

How does temperature of parcel affect buoyancy?

Answer 22

Warmer parcels are less dense/lighter (positively buoyant)
Colder parcels are more dense/heavier (negatively buoyant)

Question 23

Which mechanism for heat tranfer in the atmosphere explains: Light air rises, dense air sinks

Answer 23

Atmospheric Convection

Question 24

What does conservation of E=0 describe?

Answer 24

0 = “work done on surroundings” + “internal energy gained by air parcel

*Here, heat exchange term is zero, since no heat is added/remove

Question 25

Why/when do air parcels expand? How does that affect conservation of E? Opposite?

Answer 25

Air parcels in rising branches move into lower pressure
To equilibrate pressure with surroundings, they must expand
Expansion takes work, which, from conservation of energy, causes a loss of internal energy and cooling

*Opposite happens with sinking air parcels

Question 26

Sensible VS Latent heat

Answer 26

Sensible Heat: The heat that causes a temperature change in a substance, directly related to the kinetic energy of molecules.

Latent Heat: The energy absorbed or released during a phase change (solid, liquid, gas) without changing the temperature.

Question 27

What are the phase changes of water and how do they affect heat exchange with the environment?

Answer 27

Melting (Ice → Liquid): Absorbs heat, cools the environment.
Sublimation (Ice → Vapor): Absorbs heat, cools the environment.
Evaporation (Liquid → Vapor): Absorbs heat, cools the environment.
Freezing (Liquid → Ice): Releases heat, warms the environment.
Deposition (Vapor → Ice): Releases heat, warms the environment.
Condensation (Vapor → Liquid): Releases heat, warms the environment.

Question 28

What drives atmospheric convection, and why is it important?

Answer 28

Atmospheric convection is driven by buoyancy, where warm, less dense air rises, and cool, denser air sinks.
Important for:
-cloud formation
-weather pattern
-vertical transfer of heat in the atmosphere

Question 29

What is an adiabatic process, and how does it affect an air parcel?

Answer 29

An adiabatic process is one where no heat is exchanged between an air parcel and its surroundings.
As a parcel rises, it expands and cools due to lower pressure. Conversely, as it sinks, it compresses and warms due to higher pressure.

Question 30

How does wind chill affect the perceived temperature of the human body?

Answer 30

Wind chill increases the rate of heat loss from the body by removing the insulating warm air layer over the skin through wind (advection). It also increases evaporation from the skin, making it feel colder than the actual temperature.

Question 31

What role does latent heat play in cloud formation?

Answer 31

When moist air rises and cools, water vapor condenses into liquid droplets, releasing latent heat. This released heat warms the surrounding air, increasing its buoyancy and further promoting upward convection, essential for cloud development.